Magnetic Head Suspension

ABSTRACT

The present invention provides a magnetic head suspension, wherein a supporting portion such as an arm or base plate includes a pair of supporting pieces extending from its opposite sides in the widthwise direction to a tip-end side of the suspension, and a concave portion which is defined by the pair of supporting pieces and is opened toward the tip-end side of the suspension, there is provided an elastically-deformable elastic plate which is connected to the pair of supporting pieces at a first end and a second end in the widthwise direction of the magnetic head suspension, the member forming the load beam portion is connected to the elastic plate, and the elastic plate forms the load bending portion.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional application of U.S. patent applicationSer. No. 12/028,671, filed Feb. 8, 2008, the disclosure of which isincorporated herein in its entirety be reference thereto.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a suspension for supporting a magnetichead slider for reading and/or writing data from and/to a recordingmedium such as a hard disc device.

2. Related Art

In recent years, data storage devices for reading and/or writing datafrom and/to recording mediums through a magnetic head slider have beenwidely used in mobile apparatuses such as notebook-type personalcomputers and portable music players and, along therewith, these datastorage devices have been required to have high impact resistance.

More specifically, when such a data storage device is subjected to anexternal impulsive force with an acceleration equal to or greater than acertain value in such a direction that the magnetic head slider isseparated from a disk surface, the magnetic head slider jumps in such adirection that it separates from the disk surface and, then, swings backfrom the jump to the disc surface and impinges on the disk surface,thereby damaging the disk surface. Accordingly, in order to increase theimpact resistance of the data storage device, there is a need forraising the value of the acceleration (the critical acceleration) of anexternal impulsive force which triggers jump of the magnetic headslider.

For example, by increasing the load which presses the magnetic headslider against the disk surface, it is possible to raise the criticalacceleration.

However, it is necessary to set the load to within a proper range, inorder to control the height of the magnetic head slider above the disksurface. Accordingly, there is naturally a limit to the method whichincreases the load for suppressing the jump of the magnetic head slider.

As another structure for suppressing the jump of the magnetic headslider, there is also known a structure in which the mass of a load beamportion is reduced for reducing the inertial force applied to the loadbeam portion when an impulsive force is applied thereto, thus raisingthe critical acceleration.

However, when the thickness of the load beam portion is reduced and/or ahole is formed in the load beam portion in order to reduce the mass ofthe load beam portion, this will reduce the rigidity of the load beamportion, thus inducing the problem of degradation of the vibrationcharacteristics and the loading/unloading characteristics.

As still another structure for suppressing the jump of the magnetic headslider, there has been proposed a structure in which the load beamportion supported through a load bending portion by a supporting portionsuch as an arm or a base plate is formed to have an extending portionextending toward the base-end side of the suspension (for example, JP-A.No. 9-082052, JP-A. No. 11-039808, JP-A. No. 2004-348804, and JP-A. No.2005-174506).

The conventional structure is configured so as to makes the mass of theportion of the load beam portion which is closer to the base-end side ofthe suspension than the load bending portion to be as equal as possibleto the mass of the portion thereof which is closer to the tip-end sideof the suspension than the load bending portion. The structure isadvantageous in suppressing the jump of the magnetic head slider at atime when being subjected to an external impulsive forced withoutdegrading the rigidity of the load beam portion.

However, in the magnetic head suspensions described in these patentdocuments, the load beam portion is connected to the free end portion ofthe load bending portion which is supported by the supporting portion ina cantilever manner With these structures, the supporting point of theload beam portion (namely, the portion of the load beam portion which isconnected to the load bending portion) may vary in the directionorthogonal to the disk surface when an impulsive force is appliedthereto.

Accordingly, the magnetic head suspensions described in these patentdocuments can not sufficiently raise the critical acceleration, althoughthe problem of degradation of the rigidity of the load beam portion doesnot occur.

SUMMARY OF THE INVENTION

The present invention is made in view of the conventional techniques andaims to provide a magnetic head suspension capable of preventing, asmuch as possible, the supporting point of a load beam portion fromvarying in the direction orthogonal to a disk surface when an impact isapplied thereto, thus effectively raising the critical acceleration ofthe impact which trigger the jump action of the magnetic head slider.

The present invention provide, in order to achieve the aim, a magnetichead suspension including a load bending portion generating a load forpressing a magnetic head slider toward a disk surface, a load beamportion transmitting the load to the magnetic head slider, a supportingportion supporting the load beam portion through the load bendingportion, and a flexure portion connected to the load beam portion andsupporting the magnetic head slider, wherein the supporting portionincludes a pair of supporting pieces extending from its opposite sidesin the widthwise direction to a tip-end side of the suspension, and aconcave portion which is defined by the pair of supporting pieces and isopened toward the tip-end side of the suspension, there is provided anelastically-deformable elastic plate which is connected to the pair ofsupporting pieces at a first end and a second end in the widthwisedirection of the magnetic head suspension, the member forming the loadbeam portion is connected to the elastic plate, and the elastic plateforms the load bending portion.

According to the present invention, since the elastic plate, which issupported at its first and second ends along the widthwise direction ofthe suspension by the supporting portion in a dual-supported manner,functions as the load bending portion, it is possible to effectivelyprevent the supporting point of the load beam portion (the point of theload beam portion which is connected to the load bending portion) fromvarying in the direction orthogonal to the disk surface when theexternal impulsive force is applied thereto, thereby largely raising thecritical acceleration of the impulsive force which triggers the jump ofthe magnetic head slider.

In one embodiment, the elastic plate is twisted such that a tip end of acenter area positioned between the first and second ends comes close tothe disk surface in a state where the first and second ends arerespectively connected to the pair of supporting pieces to be bound.

In another embodiment, the pair of supporting pieces are bended atbended positions between their base ends and tip ends in such a mannerthat their tip ends come close to the disk surface. The elastic plate isconnected to the pair of supporting pieces at portions closer to the tipends than the bended positions.

Preferably, the elastic plate includes first and second connected areaswhich are respectively connected to the pair of supporting pieces, and acenter area extending between the first and second connected areas.

The center area includes a center connected portion to which a memberforming the load beam portion is connected, a first extending portionextending between the center connected portion and the first connectedarea, and a second extending portion extending between the centerconnected portion and the second connected area, the second extendingportion being symmetrical with respect to the first extending portionwith a longitudinal center line of the magnetic head suspension as areference.

More preferably, the center connected portion has a width greater thanthose of the first and second extending portions.

More preferably, the center connected portion is extended toward both atip-end side and a base-end side of the suspension with the first andsecond extending portions as a reference.

Each of the first and second extending portions preferably has, at botha tip-end side and a base-end side, outer curved portions having a widthgradually increased with decreasing distance to the correspondingconnected area, and inner curved portions having a width graduallyincreased with decreasing distance to the center connected portion.

The configuration makes it possible to stabilize the twist action of thefirst and second extending portions.

The center connected portion of the elastic plate integrally includes atip-end-side flat-surface portion which is positioned on a tip-end sideof the suspension and which is connected to a member forming the loadbeam portion at an attitude parallel to the member forming the load beamportion, a center flat-surface portion which is extended from thetip-end-side flat-surface portion toward the base-end side of thesuspension and which is inclined with respect to the tip-end-sideflat-surface portion such that it gradually separates from the memberforming the load beam portion with increasing distance from the tip-endside toward the base-end side and to which the first and secondextending portions are connected, and a base-end-side flat-surfaceportion which is extended toward the base-end side of the suspensionfrom the center flat-surface portion through a bending portion and whichis connected to the member forming the load beam portion. The centerflat-surface portion is positioned within the same plane as the plane inwhich there exist the first and second extending portions and the firstand second connected areas in a state before the magnetic headsuspension is mounted to a data storage device, and the first and secondextending portions are twisted to generate the load in a state where themagnetic head suspension is operated after being mounted to the datastorage device.

The configuration makes it possible to obtain the load in a state wherethe suspension is operated after being mounted to the data storagedevice, without performing a twisting process on the first and secondextending portions before the suspension is mounted to the data storagedevice.

In the above various configurations, the suspension preferably furtherincludes a restraint plate connected to the supporting portion so as tobe positioned on a side of a member forming the load beam portionopposite from the elastic plate in a direction orthogonal to the disksurface with the member forming the load beam portion sandwiched betweenthe restraint plate and the elastic plate. The restraint plate has asingle or plurality of protrusion portion which contacts with the memberforming the load beam portion on a load bending center line of the firstand second extending portions along the widthwise direction of thesuspension. The single or plurality of protrusion portion is placed tobe symmetrical with the longitudinal center line as a reference.

The configuration makes it possible to more effectively prevent thesupporting point of the load beam portion from varying, thereby morelargely raising the critical acceleration of the impulsive force whichtriggers the jump of the magnetic head slider.

For example, the restraint plate may have the single protrusion portion.The single protrusion portion is contacted with the member forming theload beam portion over a predetermined distance in the widthwisedirection of the magnetic head suspension.

The suspension may include, instead of the restraint plate having thesingle protrusion portion, a restraint plate having a connected surfaceconnected to the surface of the supporting portion opposite from thedisk surface, a coupling surface folded in such a direction that itcomes close to the disk surface from the connected surface, and acontact surface which is folded from the free-end side of the coupledsurface and which is connected to the surface of the member forming theload beam portion opposite from the disk surface in a surface-to-surfacemanner. A border line between the coupling surface and the contactsurface is positioned on a load bending center line of the first andsecond extending portions along the widthwise direction of thesuspension and is symmetrical with the longitudinal center line as areference.

The configuration makes it possible to more effectively prevent thesupporting point of the load beam portion from varying, thereby morelargely raising the critical acceleration of the impulsive force whichtriggers the jump of the magnetic head slider.

In the above various configurations, a member forming the load beamportion may preferably include a connected area to which the elasticplate is connected, a tip-end area extending from the connected areatoward the tip-end side of the suspension, and a base-end area extendingfrom the connected area toward the base-end side of the suspension.

More preferably, the member forming the load beam portion may haveflange portions which are provided at the opposite sides thereof in thewidthwise direction of the suspension and which extend so as to beacross the elastic plate.

The flange portions preferably have heights gradually decreased as theygo from the base end to the tip end.

In the configuration where the load beam portion includes the base-endarea, the base-end area is preferably provided with a balance massmember.

The configuration makes it possible to balance the mass of the portioncloser to the base-end side of the suspension than the load bendingcenter line with the mass of the portion closer to the tip-end side ofthe suspension than the load bending center line BL, thereby raising thecritical acceleration of the impulsive force which triggers the jump ofthe magnetic head slider.

When a longitudinal direction of the magnetic head suspension between acenter of gravity of an assembly formed by the load beam portion, theflexure portion and the balance mass member, and a load bending centerline of the first and second extending portions along the widthwisedirection of the suspension is Lg, and a length in the longitudinaldirection of the suspension between the load bending center line and thecenter of gravity of a tip-end side portion of the assembly which iscloser to the tip-end side of the suspension than the load bendingcenter line is La, the balance mass member is preferably set to have aweight so that the length Lg and the length La have a relationship of0≦Lg≦0.3×La.

The configuration makes it possible to raise the critical accelerationof the impulsive force which triggers the jump of the magnetic headslider, in various conditions in which the magnetic head suspension maybe used.

More preferably, the magnetic head suspension according to the presentinvention may further include a restriction plate connected to thesupporting portion so as to be positioned on a side closer to the disksurface than the base-end side area of the load beam portion.

The restriction plate is placed to overlap with at least a portion ofthe balance mass member in a plan view.

According to the configuration, even if the balance mass member jumps insuch a direction that it is separate from the disk surface when anexternal impulsive force is applied and then swings back toward the disksurface, it is possible to effectively prevent the balance mass memberfrom impinging on the disk surface. It is also possible to effectivelyprevent the balance mass member from impinging on the disk surface evenif an external impulsive force is applied to the balance mass member insuch a direction as to cause the balance mass member to come close tothe disk surface.

Instead of or in addition to the provision of the restriction plate, thebalance mass member may include a connected portion connected to theload beam portion and a base-end-side bending portion positioned on aside closer to the base-end side of the suspension than the connectedportion, and the balance mass member is configured so that its portionextending from the base-end-side bending portion up to a base-end edgeis gradually separated from the disk surface with decreasing distance tothe base-end edge than the connected portion.

According to the configuration, even if the balance mass member jumps insuch a direction that it is separate from the disk surface when anexternal impulsive force is applied and then swings back toward the disksurface, it is possible to effectively prevent the balance mass memberfrom impinging on the disk surface. It is also possible to effectivelyprevent the balance mass member from impinging on the disk surface evenif an external impulsive force is applied to the balance mass member insuch a direction as to cause the balance mass member to come close tothe disk surface.

The balance mass member is preferably configured so that thebase-end-side bending portion has a thickness smaller than those of theother areas of the balance mass member.

The magnetic head suspension may preferably include a signal wiringmember which has an insulation layer and a conductive layer and which isintegrally laminated on the flexure portion.

The signal wiring member includes a load-beam-portion side areasupported directly or indirectly by the load beam portion, asupporting-portion side area supported directly or indirectly by thesupporting portion, and an aerial area extending in air between theload-beam-portion side area and the supporting-portion side area.

In one embodiment, the load-beam-portion side area and the aerial areaare symmetrical with the longitudinal center line of the magnetic headsuspension as a reference, and the aerial area has at least onedirection changing portion.

In another embodiment, the load-beam-portion side area and the aerialarea are symmetrical with the longitudinal center line of the magnetichead suspension as a reference, and are placed to substantially surroundthe balance mass member in a plan view.

In the above various configurations, the elastic plate may be integrallyformed with a member forming the flexure portion.

This configuration makes it possible to reduce the number of fabricatingprocesses, thereby reducing the cost.

More preferably, the first and second extending portions of the elasticplate are provided with attenuation members which are integrallylaminated thereon and which are made of the same materials as those ofthe insulation layer and the conductive layer.

The configuration makes it possible to provide the attenuation memberswithout increasing the number of fabricating processes.

The present invention also provides, in order to achieve the aim, amagnetic head suspension including a load bending portion generating aload for pressing a magnetic head slider toward a disk surface, a loadbeam portion transmitting the load to the magnetic head slider, asupporting portion supporting the load beam portion through the loadbending portion and including a concave portion which is defined by apair of supporting pieces extending from opposite sides of thesupporting portion in the widthwise direction to a tip-end side of thesuspension and which is opened toward the tip-end side of thesuspension, and a flexure portion connected to the load beam portion andsupporting the magnetic head slider.

The suspension further including an elastically-deformable elastic platehaving first and second ends in a widthwise direction of the suspensionrespectively connected to the pair of supporting pieces, and a balancemass member having a center portion which is connected to the elasticplate, a tip-end portion which is positioned on a tip-end side of thesuspension than the center portion and which is connected to a base-endportion of the load beam portion, and a base-end portion which ispositioned on a base-end side of the suspension than the center portion.

The elastic plate includes first and second connected areas which arerespectively connected to the pair of supporting pieces, and a centerarea extending between the first and second connected areas.

The center area includes a center connected portion to which the balancemass member is connected, a first extending portion extending betweenthe center connected portion and the first connected area, and a secondextending portion extending between the center connected portion and thesecond connected area, so that the elastic plate forms the load bendingportion.

Each of the first and second extending portions preferably has, at botha tip-end side and a base-end side, outer curved portions having a widthgradually increased with decreasing distance to the correspondingconnected area, and inner curved portions having a width graduallyincreased with decreasing distance to the center connected portion.

A member forming the load beam portion may integrally include a flangearea having a center flat-plate portion positioned at the center in thewidthwise direction of the suspension and a pair of flange portionsprovided at the opposite sides of the center flat-plate portion in thewidthwise direction of the suspension, an elastic-plate area forming theelastic plate, and a flat-plate shaped coupling area which couples thecenter flat-plate portion of the flange area to a tip-end edge of thecenter connected portion of the elastic plate.

The configuration makes it possible to reduce the cost thanks toreduction of the number of members and assembling processes.

The tip-end portion of the balance mass member is preferably connectedto the center flat-plate portion of the load beam portion, at a statewhere the tip-end portion of the balance mass member is interposedbetween the pair of flange portions.

More preferably, the balance mass member may have a tip-end-side bendingportion at a portion corresponding to the coupling area.

In the configuration, the coupling area preferably has a width smallerthan that of the base-end portion of the flange area.

In the above various configurations, the balance mass member preferablyincludes a base-end-side bending portion at the base-end portion, and isconfigured so that its portion extending from the base-end-side bendingportion up to a base-end edge is gradually separated from the disksurface with decreasing distance to the base-end edge.

The balance mass member is preferably configured so that the bendingportion has a thickness smaller than those of the other areas of thebalance mass member.

In the above various configurations, the center connected portion of theelastic plate preferably includes a tip-end-side flat-surface portionwhich is positioned on a tip-end side of the suspension and which isconnected to the center portion of the balance mass member at anattitude parallel to the center portion of the balance mass member, acenter flat-surface portion which is extended from the tip-end-sideflat-surface portion toward the base-end side of the suspension andwhich is inclined with respect to the tip-end-side flat-surface portionsuch that it gradually separates from the center portion of the balancemass member with increasing distance from the tip-end side toward thebase-end side and to which the first and second extending portions areconnected, and a base-end-side flat-surface portion which is extendedtoward the base-end side of the suspension from the center flat-surfaceportion through a bending portion and which is connected to the centerportion of the balance mass member at an attitude parallel to the centerportion of the balance mass member.

The center flat-surface portion is positioned within the same plane asthe plane in which there exist the first and second extending portionsand the first and second connected areas in a state before the magnetichead suspension is mounted to a data storage device, and the first andsecond extending portions are twisted to generate the load in a statewhere the magnetic head suspension is operated after being mounted tothe data storage device.

The configuration makes it possible to obtain the load in a state wherethe suspension is operated after being mounted to the data storagedevice, without performing a twisting process on the first and secondextending portions before the suspension is mounted to the data storagedevice.

In the above various configurations, when a length in the longitudinaldirection of the magnetic head suspension between a center of gravity ofan assembly formed by the load beam portion, the flexure portion and thebalance mass member, and a load bending center line of the first andsecond extending portions along the widthwise direction of thesuspension is Lg, and a length in the longitudinal direction of thesuspension between the load bending center line and the center ofgravity of a tip-end side portion of the assembly which is closer to thetip-end side of the suspension than the load bending center line is La,Lg and La is preferably set to have a relationship of 0≦Lg≦0.3×La.

In the above various configuration, the pair of supporting piecespreferably have base-end portions which are positioned on the base-endside of the suspension, and tip-end portions which are positioned on thetip-end side of the suspension than the base-end portions and to whichthe elastic plate is connected, and the base-end portions have widthsgreater than those of the tip-end portions.

This configuration makes it possible to raise the resonance frequency ofthe supporting portion 610 in the twisting mode, thereby improving thepositioning accuracy in moving the magnetic head slider to a targettrack.

BRIEF DESCRIPTION OF THE DRAWINGS

The above, and other objects, features and advantages of the presentinvention will become apparent from the detailed description thereof inconjunction with the accompanying drawings wherein.

FIGS. 1A and 1B are a top view and a bottom view of a magnetic headsuspension according to a first embodiment of the present invention,respectively.

FIG. 2 is a perspective view of the magnetic head suspension shown inFIGS. 1A and 1B.

FIG. 3 is a perspective view of a magnetic head suspension modified fromthe suspension according to the first embodiment so as to have a baseplate as a supporting portion.

FIG. 4 is a top view of the supporting portion of the magnetic headsuspension according to the first embodiment.

FIG. 5 is a bottom view of an elastic plate of the magnetic headsuspension according to the first embodiment.

FIGS. 6A and 6B are perspective views of the magnetic head suspensionaccording to the first embodiment in a state before it is mounted to adata storage device and in a state where it operated after being mountedto the date storage device, respectively.

FIG. 7 is a bottom view of an exemplary modification of the elasticplate of the magnetic head suspension according to the first embodiment.

FIGS. 8A and 8B are perspective views of the elastic plate shown in FIG.7 in a state of being twisted and in a state of being twisted back,respectively.

FIGS. 9A to 9C are a top view of a modified magnetic head suspensionhaving a different structure for generating the load by the elasticplate, a side view of the same before it is mounted to the data storagedevice, and a side view of the same in a state where it is operatedafter being mounted to the data storage device, respectively.

FIG. 10 is a partially-enlarged top view of the magnetic head suspensionaccording to the first embodiment.

FIGS. 11A to 11D are a top view of a load beam portion of the magnetichead suspension according to the first embodiment, a side view thereof,a cross-sectional view taken along the line c-c in FIG. 11A, and across-sectional view taken along the line d-d in FIG. 11A, respectively.

FIGS. 12A and 12B are a top view of a bottom view of a conventionalmagnetic head suspension having a load bending portion supported in acantilever manner, respectively.

FIG. 13 is a graph showing the results of analyses of the criticalacceleration on the basis of a finite-element method in an example(example 1) of the magnetic head suspension according to the firstembodiment, an example (example 2) of a magnetic head suspensionmodified from the first embodiment, and examples (comparative example 1and 2) of the conventional magnetic head suspension, when impulsivewaves having pulse widths of 1.00 msec, 1.50 msec and 2.00 msec areapplied thereto.

FIG. 14 is a graph showing the results of the analyses, on the basis ofa finite-element method, for the critical acceleration in the example 1,when the ratio K=Lg/La (center-of-gravity position ratio) of the lengthLg between the center of gravity (entire gravity) of the assembly formedby the load beam portion, the flexure portion and the balance massmember, and a load bending center line of the elastic plate to thelength La between the center of gravity (tip-end side gravity) of thetip-end side portion of the assembly which is closer to the tip-end sideof the suspension than the load bending center line and the load bendingcenter line is varied.

FIGS. 15A to 15C are a top view of a load beam portion modified from theload beam portion of the magnetic head suspension according to the firstembodiment, a side view thereof, and a cross-sectional view taken alongthe line c-c in FIG. 15A, respectively.

FIG. 16 is a graph showing the results of the analyses, on the basis ofa finite-element method, on an example (example 3) of the magnetic headsuspension having the flange portions structured such that their heightsare gradually decreased as they go from the base end to the tip end andan example (example 4) of the magnetic head suspension having flangeportions having substantially a constant height, when impulsive waveshaving pulse widths of 1.00 msec, 1.50 msec and 2.00 msec are appliedthereto.

FIGS. 17A and 17B are bottom views of an example and alternative exampleof a modified magnetic head suspension which is modified from the firstembodiment so as to have a signal wiring member integrally laminated ona flexure portion, respectively.

FIG. 18 is a partially-enlarged bottom view of the alternative exampleof the modified magnetic head suspension in which the signal wiringmember integrally laminated on the flexure portion.

FIGS. 19A to 19C are, respectively, a top view of a magnetic headsuspension according to a second embodiment of the present invention, abottom view thereof, and a cross-sectional view taken along the line c-cin FIG. 19A.

FIG. 20 is a perspective view of the magnetic head suspension accordingto the second embodiment.

FIG. 21 is a graph showing the results of analyses of the criticalaccelerations in an example (the example 1) of the magnetic headsuspension according to the first embodiment and an example (example 5)of the magnetic head suspension according to the second embodiment,which are resulted from the application of impulsive waves having pulsewidths of 1.00 msec, 1.50 msec and 2.00 msec thereto, on the basis of afinite-element method.

FIGS. 22A and 22B are a top view of a magnetic head suspension modifiedfrom the second embodiment and a cross-sectional view taken along theline b-b in FIG. 22A, respectively.

FIGS. 23A to 23C are a top view of a magnetic head suspension modifiedfrom the second embodiment, a cross-sectional view taken along the lineb-b in FIG. 23A and a cross-sectional view taken along the line c-c inFIG. 23A, respectively.

FIGS. 24A to 24C are a top view of a magnetic head suspension accordingto a third embodiment of the present invention, a bottom view thereof,and a cross-sectional view taken along the line c-c in FIG. 24A,respectively.

FIGS. 25A and 25B are a top view and a bottom view of a magnetic headsuspension according to a fourth embodiment of the present invention,respectively.

FIGS. 26A and 26B are partial side views of the magnetic head suspensionaccording to the fourth embodiment in a state before it is mounted to adata storage device and in a state where it is operated after beingmounted to the data storage device, respectively.

FIG. 27 is a perspective view of the magnetic head suspension accordingto the fourth embodiment before being mounted to the data storagedevice.

FIG. 28 is an exploded perspective view of the magnetic head suspensionaccording to the fourth embodiment before being mounted to the datastorage device.

FIGS. 29A and 29B are, respectively, a top view and a bottom view of abalance mass member of the magnetic head suspension according to thefourth embodiment.

FIG. 30A is a plan view of an elastic plate of the magnetic headsuspension according to the fourth embodiment.

FIG. 30B is a plan view of an exemplary modification of the elasticplate.

FIGS. 31A and 31B are a top view and a bottom view of a magnetic headsuspension according to a fifth embodiment of the present invention,respectively.

FIGS. 32A and 32B are partial side views of the magnetic head suspensionaccording to the fifth embodiment in a state before it is mounted to adata storage device and in a state where it is operated after beingmounted to the data storage device, respectively.

FIG. 33 is a perspective view shown from the disk-surface side of themagnetic head suspension according to the fifth embodiment in a statewhere it is operated after being mounted to the data storage device.

FIG. 34 is a perspective view shown from the disk-surface side of theelastic plate of the magnetic head suspension according to the fifthembodiment.

FIGS. 35A and 35B are a top view and a bottom view of a magnetic headsuspension according to a sixth embodiment of the present invention,respectively.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

Hereinafter, one preferred embodiment of a magnetic head suspensionaccording to the present invention will be described, with reference tothe attached drawings.

FIGS. 1A and 1B illustrate a top view of a magnetic head suspension 1Aaccording to the present embodiment (a view illustrating the sideopposite from a disk surface) and a bottom view of the same (a viewillustrating the disk-surface side), respectively.

Further, FIG. 2 illustrates a perspective view of the magnetic headsuspension 1A. In FIG. 1, the reference character 90 designates weldingpositions.

The magnetic head suspension 1A includes a load bending portion 20 whichgenerates a load for pressing a magnetic head slider 100 against thedisk surface, a load beam portion 30 which transmits the load to themagnetic head slider 100, a supporting portion 10 which supports theload beam portion 30 through the load bending portion 20, and a flexureportion 40 which is connected to the load beam portion 30 and supportsthe magnetic head slider 100.

The supporting portion 10 includes a main-body portion, a pair ofsupporting pieces 11 extending toward the tip end from the oppositesides of the main-body portion in the widthwise direction of thesuspension, and a concave portion 12 which is defined by the pair ofsupporting pieces 11 so as to open to the tip-end side of thesuspension, as illustrated in FIG. 1 and FIG. 2.

In the present embodiment, as illustrated in FIG. 1 and FIG. 2, thesupporting portion 10 is formed to be an arm. The supporting portion 10can be formed from a stainless-steel plate having a thickness in therange of about 0.1 mm to 0.8 mm.

Further, as illustrated in FIG. 3, the supporting portion 10 can also beformed to be a base plate including a boss portion 15 to be connected toa tip end of an arm of an E block through swage processing, instead ofthe arm.

The load beam portion 30 is a member for transmitting the load generatedfrom the load bending portion 20 to the magnetic head slider 100 asdescribed above and, therefore, is required to have a predeterminedrigidity.

Accordingly, the load beam portion 30 is preferably formed from a memberhaving a thickness greater than those of the load bending portion 20 andthe flexure portion 40. The load beam portion 30 is formed from astainless-steel plate having a thickness in the range of about 0.02 mmto 0.1 mm.

The load beam portion 30 is provided, at its tip-end portion, with aprotrusion 31 which is a so-called dimple.

The protrusion 31 is protruded by, for example, about 0.05 mm to 0.1 mm,in such a direction that it comes close to the disk surface. Theprotrusion 31 is contacted with a back surface (a surface opposite fromthe disk surface) of a head mounting area 43 of the flexure portion 40,so that the load is transmitted to the head mounting area 43 of theflexure portion 40 through the protrusion 31.

Further, the detailed structure of the load beam portion 30 will bedescribed later.

The flexure portion 40 is supported by the load beam portion 30 in astate where it supports the magnetic head slider 100.

More specifically, as illustrated in FIG. 1, the flexure portion 40includes a main-body area 41 bonded to the lower surface of the loadbeam portion 30 (the surface thereof which faces to the disk surface)through welding or the like, a pair of supporting pieces 42 extendingtoward the tip-end side of the suspension from the main-body area 41,and the head mounting area 43 supported by the supporting pieces 42.

The head mounting area 43 supports the magnetic head slider 100 at itssurface which faces to the disk surface.

As described above, the protrusion 31 is contacted with the back surfaceof the head mounting area 43, which allows the head mounting area 43 tosway flexibly in the direction of roll and in the direction of pitch,with the protrusion 31 used as a fulcrum.

The flexure portion 40 is formed from a member having lower rigiditythan that of the load beam portion 30, in order to allow the headmounting area 43 to swing in the direction of roll and in the directionof pitch. The flexure portion 40 is formed from a stainless-steel platehaving a thickness in the range of about 0.015 mm to 0.025 mm, forexample.

In the present embodiment, the load bending portion 20 is formed from anelastic plate 50 which is supported in a dual-supported manner.

FIG. 4 illustrates a top view of the supporting portion 10 of themagnetic head suspension 1A according to the present embodiment.

As illustrated in FIGS. 1 to 4, the supporting portion 10 includes themain-body portion, the pair of supporting pieces 11 extending toward thetip-end side of the suspension from the opposite sides of the main-bodyportion in the widthwise direction of the suspension, and the concaveportion 12 which is defined by the pair of supporting pieces 11 so as toopen to the tip-end side of the suspension.

Further, the magnetic head suspension 1A includes theelastically-deformable elastic plate 50 which is connected to the pairof supporting pieces 11 at first and second ends in the widthwisedirection of the magnetic head suspension, and the elastic plate 50supports the load beam portion 30 such that the elastic plate 50 canform the load bending portion 20.

FIG. 5 illustrates a bottom view of the elastic plate 50.

As illustrated in FIG. 1, FIG. 2 and FIG. 5, the elastic plate 50extends in the widthwise direction of the magnetic head suspension 1A ina state where it is supported at its opposite ends by the pair ofsupporting pieces 11.

In the present embodiment, the elastic plate 50 is connected to thebottom surfaces of the pair of supporting pieces 11 which are faced tothe disk surface and also supports the load beam portion 30 at its uppersurface opposite from the disk surface.

The elastic plate 50 includes first and second connected areas 51 a and51 b which are connected to the pair of supporting pieces 11,respectively, and a center area 52 extending between the first andsecond connected areas 51 a and 51 b, as illustrated in FIG. 1 and FIG.5.

The center area 52 includes a center connected portion 52 c to which themember forming the load beam portion 30 is connected, a first extendingportion 52 a extending between the center connected portion 52 c and thefirst connected area 51 a, and a second extending portion 52 b extendingbetween the center connected portion 52 c and the second connected area51 b, wherein the first extending portion 52 a and the second extendingportion 52 b are shaped to be symmetrical with the longitudinal centerline CL of the magnetic head suspension 1A as a reference.

The elastic plate 50 is twisted such that the tip end of the center area52 comes close to the disk surface in a state where the first and secondconnected areas 51 a and 51 b are respectively connected to the pair ofsupporting pieces 11 and, thus, the elastic plate 50 is bound at itsopposite ends, thereby generating the load.

FIG. 6A and FIG. 6B illustrate a perspective view of the magnetic headsuspension 1A including the elastic plate 50 in a state before thesuspension 1A is mounted to a data storage device, and a perspectiveview of the magnetic head suspension 1A in a state where the magnetichead slider 100 is floated above the disk surface due to the airpressure caused by the rotation of the disk surface in the data storagedevice during the magnetic head suspension 1A is operated after beingmounted to the data storage device.

Before the magnetic head suspension 1A is mounted to the data storagedevice such as a hard disk device, the elastic plate 50 is twisted suchthat the tip end of the center area 52 of the elastic plate 50 comesclose to the disk surface, which causes the load beam portion 30 to takean attitude inclined with respect to the supporting portion 10 such thatits tip end comes close to the disk surface, as illustrated in FIG. 6A.

As illustrated in FIG. 6B, in a state where the magnetic head suspension1A operates to read and/or write data with the magnetic head slider 100,the elastic plate 50 is twisted back due to the air pressure caused bythe rotation of the disk surface, which causes the load beam portion 30to be substantially parallel to the disk surface, thereby causing themagnetic head slider 100 to float above the disk surface and to bemaintained in a state where it can read and/or write data from and/or tothe disk surface.

At this state, since the elastic plate 50 is twisted back due to the airpressure, the elastic plate 50 possess elasticity in such a directionthat it presses the tip end of the load beam portion 30 against the disksurface. This possessed elasticity functions as the load for pressingthe magnetic head slider 100 against the disk surface.

FIG. 7 is a bottom view of an exemplary modification 50B of the elasticplate 50.

Preferably, as illustrated in FIG. 7, the elastic plate 50B is formedsuch that the center connected portion 52 c has a width greater thanthat of the first and second extending portions 52 a and 52 b.

With this structure, it is possible to easily perform the process fortwisting the elastic plate 50B, while easily securing portions of theelastic plate 50B to which the load beam portion 30 is welded.

FIGS. 8A and 8B illustrate, respectively, a top perspective viewillustrating a state where the elastic plate 50B according to themodification example is twisted (a state before the magnetic headsuspension 1A is mounted to the data storage device), and a topperspective view illustrating a state where the elastic plate 50B hasbeen twisted back (a state where the elastic plate 50B has been twistedback due to the air pressure during the magnetic head suspension 1A isoperated after being mounted to the data storage device).

More preferably, as illustrated in FIG. 7 and FIG. 8, the centerconnected portion 52 c is extended toward the tip-end side and towardthe base-end side of the suspension, such that the center connectedportion 52 c is symmetrical with the load bending center line BL of thefirst and second extending portions 52 a and 52 b extended in thewidthwise direction of the magnetic head suspension as a reference.

With this structure, it is possible to easily perform the process fortwisting the elastic plate 50B about the load bending center line BL,while offering the aforementioned effects.

More preferably, as illustrated in FIG. 7 and FIG. 8, the elastic plate50B is formed such that the first and second connected areas 51 a and 51b have a width greater than that of the first and second extendingportions 52 a and 52 b.

With this structure, it is possible to easily perform the process fortwisting the elastic plate 50B, while securing portions of the first andsecond connected areas 51 a and 51 b to which the pair of supportingpieces 11 are welded.

Further, in the present embodiment, as previously described, theprocessing for twisting the elastic plate 50, 50B is performed beforethe magnetic head suspension 1A is mounted to the data storage deviceand, further, the elastic plate 50, 50B is twisted back through the airpressure in a state where the magnetic head suspension 1A is operated,in order to generate the load. However, instead of this structure, it isalso possible to employ the following structure.

FIG. 9 illustrates a magnetic head suspension 1B according to a modifiedembodiment for causing the elastic plate 50, 50B to generate the load.Further, FIGS. 9A to 9C illustrate, respectively, a top view of themagnetic head suspension 1B according to the modified embodiment, a sideview of the same before it is mounted to the data storage device, and aside view of the same in a state where it is operated after beingmounted to the data storage device.

As illustrated in FIG. 9, in the magnetic head suspension 1B accordingto the modified embodiment, the pair of supporting pieces 11 are bendedat a bended position 11 a between the base end and the tip end in such amanner that their tip ends come close to the disk surface, and theelastic plate 50 is connected to the pair of supporting pieces 11 at aportion closer to the tip end than the bended position 11 a.

That is, before the magnetic head suspension 1B is mounted to the datastorage device, the load beam portion 30 takes an attitude inclined suchthat it gradually comes close to the disk surface with decreasingdistance to the tip end, as illustrated in FIG. 9B.

Further, in a state where the magnetic head suspension 1B is operatedafter being mounted to the data storage device, the elastic plate 50 istwisted through the air pressure such that the load beam portion 30 issubstantially parallel to the disk surface, which causes the elasticplate 50 to generate the load (see FIG. 9C).

As described above, the magnetic head suspension 1A according to thepresent embodiment and the magnetic head suspension 1B according to themodified embodiment illustrated in FIG. 9 are configured so that theelastic plate 50, 50B which is supported at its opposite ends functionsas the load bending portion 20, thereby offering effects as follows.

That is, a conventional magnetic head suspension includes a load bendingportion formed to be a cantilever spring which is supported at itsbase-end portion by a supporting portion such as an arm and supports aload beam portion at its free end portion.

With this conventional structure, when an external impulsive force isapplied thereto, this will largely vary the supporting point of the loadbeam portion (namely, the point of the load beam portion to which theload bending portion is connected), in the direction orthogonal to thedisk surface. Accordingly, even if the weight of the load beam portionis reduced without involving the reduction of the rigidity thereofand/or the masses of the tip-end side and the base-end side of the loadbeam portion as the supporting point of the load beam portion as areference are balanced, it is impossible to suppress sufficiently thejump of the magnetic head slider in the direction orthogonal to the disksurface.

On the contrary, the magnetic head suspension 1A according to thepresent embodiment and the magnetic head suspension 1B according to themodified embodiment are configured so that the elastic plate 50, 50Bsupported at its opposite ends functions as the load bending portion 20.

With this structure, when an external impulsive force is appliedthereto, it is possible to effectively prevent the supporting point ofthe load beam portion 30 (namely, the point of the member forming theload beam portion 30 which is connected to the elastic member 50, 50B)from varying in the direction orthogonal to the disk surface, thussuppressing the jump of the magnetic head slider 100 and largely raisingthe critical acceleration of the impulsive force which triggers the jumpof the magnetic head slider 100.

Further, in the magnetic head suspension 1B according to the modifiedembodiment illustrated in FIG. 9, it is possible to set the value of theload, through the bending angle of the pair of supporting pieces 11.This can offer the advantage of stably controlling the load.

Further, the elastic plate 50, 50B is made of a member capable ofgenerating the load by its twisting action. That is, the elastic plate50, 50B is formed from a member having a thickness smaller than that ofthe load beam portion 30 and can be preferably formed from, for example,a stainless-steel plate having a thickness in the range of about 0.02 mmto 0.1 mm.

FIG. 10 illustrates a partially-enlarged top view of the magnetic headsuspension 1A.

Preferably, the load beam portion 30 includes a base-end area 30 bextending from the elastic plate 50 toward the base end, in addition toa tip-end area 30 a which extends from the elastic plate 50 toward thetip end and supports the flexure portion 40, as illustrated in FIG. 10.

That is, the member forming the load beam portion 30 includes aconnected area 30 c connected to the elastic plate 50, the tip-end area30 a extending from the connected area 30 c toward the tip-end side ofthe suspension, and the base-end area 30 b extending from the connectedarea 30 c toward the base-end side of the suspension.

The base-end area 30 b provided in the load beam portion 30 makes itpossible to balance the mass of the portion of the load beam portion 30closer to the base end of the suspension than the load bending centerline BL with the mass of the portion of the load beam portion 30 closerto the tip-end side of the suspension than the load bending center lineBL.

FIG. 11 illustrates the load beam portion 30, wherein FIGS. 11A to 11Dare a top view thereof; a side view thereof, a cross-sectional viewtaken along the line c-c in FIG. 11A, and a cross-sectional view takenalong the line d-d in FIG. 11A, respectively.

As illustrated in FIG. 10 and FIG. 11, the member forming the load beamportion 30 has flange portions 35 extending at the opposite sidesthereof in the longitudinal direction of the suspension so as to beacross the elastic plate 50.

More preferably, the flange portions 35 are configured such that theirheights gradually decrease as it goes from the base end to the tip end.

With this structure, it is possible to increase the mass of the base-endarea 30 b of the load beam portion 30 with respect to the mass of thetip-end area 30 a while increasing the rigidity of the load beam portion30, which can effectively balance the mass of the portion of the loadbeam 30 closer to the base-end side of the suspension than the loadbending center line BL with the mass of the portion of the load beamportion 30 closer to the tip-end side of the suspension than the loadbending center line BL.

The magnetic head suspension 1A according to the present embodimentincludes a balance mass member 60 secured to the base-end area 30 b ofthe load beam portion 30, in addition to the structure explained above,as illustrated in FIGS. 1, 2, 3, 9 and 10.

By providing the balance mass member 60, it is possible to balance themass of the portion of the load beam portion 30 closer to the base-endside of the suspension than the elastic plate 50 with the mass of theportion of the load beam portion 30 closer to the tip-end side of thesuspension, while reducing the length of the base-end area 30 b as muchas possible.

In the present embodiment, the base-end area 30 b is configured toposition in the concave portion 12 in a plan view.

Hereinafter, there will be described the results of analyses of thecritical acceleration (the acceleration of an impulsive force whichtriggers the jump of the magnetic head slider 100) in an example(hereinafter, referred to as an example 1) of the magnetic headsuspension 1A according to the present embodiment, and the criticalacceleration in an example (hereinafter, referred to as a comparativeexample 1) of the conventional magnetic head suspension illustrated inFIG. 12, on the basis of a finite-element method.

The aforementioned analyses were performed under the followingcondition.

In the example 1, the supporting portion 10, the load beam portion 30,the elastic plate 50 forming the load bending portion 20 and the flexureportion 40 are all made of stainless-steel plates (SUS304) havingthicknesses of 0.4 mm, 0.025 mm, 0.02 mm and 0.02 mm, respectively.

In the example 1, a length La (see FIG. 10) in the longitudinaldirection of the magnetic head suspension between the load bendingcenter line BL and the center of gravity DG of the tip-end side portionof the assembly constituted by the load beam portion 30, the flexureportion 40 and the balance mass member 60 which is closer to the tip-endside of the suspension than the load bending center line BL was set to3.316 mm. Further, a length Lg (see FIG. 10) in the longitudinaldirection of the magnetic head suspension between the center of gravityWG of the entire assembly and the load bending center line BL was set to0.25 mm. Further, a length Lb (see FIG. 10) in the longitudinaldirection of the magnetic head suspension between the load bendingcenter line BL and the center of gravity PG of the base-end side portionof the aforementioned assembly which is closer to the base-end side ofthe suspension than the load bending center line BL was set to 1.54 mm.It is preferable to make the position of the center of gravity of theportion of the aforementioned assembly which is closer to the base-endside of the suspension than the load bending center line BL to be closerto the bending load center line BL as much as possible, in order toprevent the reduction of the resonance frequency of the magnetic headsuspension 1A, particularly the SWAY-mode frequency (the resonance-modefrequency at a time when the magnetic head slider 100 is moved in theseek direction parallel to the disk surface).

The comparative example 1 has an elastic plate 150 supported in acantilever manner by the supporting portion 10 as illustrated in FIG.12, instead of the elastic plate 50 supported at its opposite ends bythe supporting portion 10.

More specifically, the elastic plate 150 has a pair of elastic pieces151 supported at their base ends by the pair of supporting pieces 11,and a coupling piece 152 coupling the free end portions of the pair ofelastic pieces 151 to each other, wherein the load beam portion 30 isconnected to the coupling piece 152.

In the comparative example 1 having the aforementioned structure, theelastic pieces supported in a cantilever manner functions as a loadbending portion for generating the load for pressing the magnetic headslider 100 against the disk surface.

The analysis on the comparative example 1 was performed under the samecondition as that for the example 1, except that the thickness of theelastic plate 150 was set to 0.034 mm.

Analyses were performed for the critical accelerations of the example 1and the comparative example 1 when impulsive waves (half-sine waveaccelerations) having pulse widths of 1.00 msec, 1.50 msec and 2.00 msecwere applied thereto, on the basis of a finite-element method. FIG. 13illustrates the results of the analyses.

As illustrated in FIG. 13, the critical acceleration in the example 1 ishigher than that in the comparative example 1, for any of the impulsivewaves having the pulse widths.

More specifically, it is revealed that the critical acceleration in theexample 1 becomes higher as the pulse width of the impulsive wave isincreased, while the critical acceleration in the comparative example 1is substantially constant for any of the pulse widths. Tae impulsivewave having a pulse width of 1.00 msec corresponds to an impact on thedata storage device when the data storage device is fallen on arelatively-hard material such as a concrete. The impulsive wave having apulse width of 2.00 msec corresponds to an impact on the data storagedevice when the data storage device is fallen on a relatively-softmember such as a wood desk, for example.

The same analyses were performed on an example (hereinafter, referred toas an example 2) of the magnetic head suspension provided by eliminatingthe balance mass member 60 from the example 1 and an example(hereinafter, referred to as a comparative example 2) of the magnetichead suspension provided by eliminating the balance mass member 60 fromthe comparative example 1. The results of these analyses are alsoillustrated in FIG. 13.

As is apparent from FIG. 13, the critical acceleration in the example 2is higher than that in the comparative example 2 for any of theimpulsive waves having the pulse widths, also in a configuration havingno balance mass member 60.

Further, analyses were performed, on the basis of a finite-elementmethod, for the critical acceleration in the example 1, when the ratioK=Lg/La (hereinafter, referred to as center-of-gravity position ratio)of the length Lg between the center of entire gravity WG and the loadbending center line BL to the length La between the center of tip-endside gravity DG and the load bending center line BL was varied. FIG. 14illustrates the results of the analyses.

Please note that the range of K<0 means that the mass of the balancemass member 60 is set such that the position of the center of thegravity WG of the entire assembly is closer to the base-end side of thesuspension than the load bending center line BL.

As is apparent from FIG. 14, in the range of K<0, the criticalacceleration for an applied impulsive wave having an acceleration pulsewidth of 1.0 msec is suddenly decreased.

Further, as is apparent from FIG. 14, it is revealed that, within therange of K≦0.45, the example 1 has a critical accelerationcharacteristic equal to or higher than that of the comparative example 1for all of the pulse widths.

Accordingly, it is preferable that the center-of-gravity position ratioK falls in the range of 0≦K≦0.45.

Further, as is apparent from FIG. 14, within the range of K≦0.3, thecritical acceleration in the example 1 is clearly higher than that inthe comparative example 1, for an impulsive wave having a pulse width of2.0 msec, that is in the case where the data storage device fallen on arelatively-soft material such as a wood desk.

Accordingly, it is preferable to set the mass of the balance mass member60 such that K falls within the range of 0≦K≦0.3, according to thecondition under which the data storage device utilizing the magnetichead suspension is used.

Further, it is revealed that, within the range of K≦0.2, the criticalacceleration in the example 1 is higher than that in the comparativeexample 1, for all of the impulsive waves having the pulse waves.

Accordingly, it is more preferable to set the mass of the balance massmember 60 such that K falls within the range of 0≦K≦0.2.

Further, analyses were performed, on the basis of a finite-elementmethod, on an example (hereinafter, referred to as an example 3, seeFIG. 11) of the magnetic head suspension 1A having the flange portions35 structured such that their heights were gradually decreased as theywent from the base end to the tip end and an example (hereinafter,referred to as an example 4, see FIG. 15) of the magnetic headsuspension having flange portions 35 having substantially a constantheight, when impulsive waves having pulse widths of 1.00 msec, 1.50 msecand 2.00 msec were applied thereto. FIG. 16 illustrates the results ofthe analyses.

In the example 3, the flange portions 35 are folded at an angle of 75°and also has a height of 0.345 mm at its portion closest to the base endand has a height of 0.160 mm at its portion closest to the tip end. Onthe other hand, in the example 4, the flange portions 35 are folded atthe same angle as that of the example 3 and also has a constant heightof 0.180 mm from its portion closest to the base end to its portionclosest to the tip end.

As is apparent from FIG. 16, the example 3 having the flange portions 35formed such that their heights are gradually decreased from the base endto the tip end exhibits a higher critical acceleration than that of theexample 4 having the flange portion 35 having the constant height, forall of the pulse widths.

Preferably, a signal wiring member 70 which is electrically connected ata first end to the magnetic head slider 100 and also is capable ofoutputting electrical signals to the outside at a second end thereof canbe laminated on the flexure portion 40, such that the signal wiringmember 70 is integral with the flexure portion 40.

FIGS. 17A and 17B illustrate bottom views illustrating an example 1C andan alternative example 1D of the magnetic head suspension 1C having thesignal wiring member 70 laminated on the flexure portion 40 such thatthey are integral with each other.

More specifically, as illustrated in FIG. 17, the signal wiring member70 includes an insulation layer 71 laminated on the member forming theflexure portion 40 and a conductive layer 72 laminated on the insulationlayer 71 and, preferably, can further include a protective layer (notillustrated) covering the conductive layer.

In the structure including the signal wiring member 70 formed integrallywith the flexure portion 40, the signal wiring member 70 preferablyincludes a load-beam-portion side area 70 a supported directly orindirectly by the load beam portion 30 through the flexure portion 40, asupporting-portion side area 70 b supported directly or indirectly bythe supporting portion 10, and an aerial area 70 c extending in airbetween the load-beam-portion side area 70 a and the supporting-portionside area 70 b.

In the magnetic head suspension 1C illustrated in FIG. 17A, theload-beam-portion side area 70 a and the aerial area 70 c aresymmetrical with the longitudinal center line CL of the magnetic headsuspension as a reference and, also, the aerial area 70 c has at leastone direction changing portion 74.

In the magnetic head suspension 1D illustrated in FIG. 17B, theload-beam-portion side area 70 a and the aerial area 70 c aresymmetrical with the longitudinal center line BL of the magnetic headsuspension as a reference and, also, are placed to substantiallysurround the balance mass member 60 in a plan view.

With the example 1C and the alternative example 1D, it is possible toeffectively prevent the signal wiring member from interfering with themovement of the balance mass member 60 when the impulsive wave wasapplied thereto.

Further, in the embodiment illustrated in FIG. 17A, the directionchanging portion 74 has a U-shape in a plan view, which may inducevibrations of the U-shaped portion in a plan view due to the air flowscaused by the rotation of the disk. However, in the embodimentillustrated in FIG. 17B, it is possible to prevent the influence of theair flows caused by the rotation of the disk.

Further, the magnetic head assemblies 1C and 1D include an elastic plate50C configured to form both the load bending portion 20 and the flexureportion 40 as illustrated in FIGS. 17A and 17B.

That is, the elastic plate 50C is formed integrally with the memberforming the flexure 40.

With this structure, it is possible to reduce the number of assemblingprocesses and simplify the fabrication processes.

More preferably, as illustrated in FIG. 18, the first and secondextending portions 52 a and 52 b of the elastic plate 50C are providedwith attenuation members 75 including viscoelastic members, which canstop the vibration of the elastic plate 50C as rapidly as possible.

The attenuation members 75 are placed to be symmetrical with thelongitudinal center line as a reference. In the embodiment illustratedin FIG. 18, there are provided a pair of attenuation members 75 placedto be symmetrical to each other with the longitudinal center line as areference.

In the structure including the elastic plate 50C formed integrally withthe member forming the flexure portion 40 and also including the signalwiring member 70 laminated on the flexure portion 40 such that they areintegral with each other, the attenuation members 75 are preferably madeof the same materials as those of the insulation layer 71 and theconductive layer 72.

That is, it is preferable to laminate the attenuation members 75 formedby the insulation layer 71 and the conductive layer 72 on the first andsecond extending portions 52 a and 52 b, at the same time as laminatingthe insulation layer 71 and the conductive layer 72 on the flexureportion 40, which can form the attenuation members 75 without increasingthe number of fabrication processes.

Further, the conductive layer 72 can be made of a metal such as Cu, andthe insulation layer 71 can be made of a resin such as polyimide.

Second Embodiment

Hereinafter, there will be described another embodiment of the magnetichead suspension according to the present invention with reference to theattached drawings.

FIGS. 19A to 19C illustrate, respectively, a top view of a magnetic headsuspension 2A according to the second embodiment, a bottom view of thesame, and a cross-sectional view taken along the line c-c in FIG. 19A.

Further, FIG. 20 illustrates a perspective view of the magnetic headsuspension 2A.

Further, in the drawings, the same components as those of the firstembodiment are designated by the same reference characters and will notbe described in detail.

As illustrated in FIG. 19 and FIG. 20, the magnetic head suspension 2Aincludes a restraint plate 80 connected to the supporting portion 10 andpositioned on a side of the member forming the load beam portion 30opposite from the elastic plate 50 so that the member forming the loadbeam portion 30 is sandwiched between the restraint plate 80 and theelastic plate 50 in the direction orthogonal to the disk surface, inaddition to the structure of the magnetic head suspension 1A accordingto the first embodiment.

The restraint plate 80 has a protrusion portion 81 which contacts withthe member forming the load beam portion 30 on the load bending centerline BL, as illustrated in FIGS. 19A and 19C.

In the present embodiment, as illustrated in FIG. 19, the elastic plate50 is connected to the lower surface of the supporting portion 10 and,also, the member forming the load beam portion 30 is connected to theupper surface of the elastic plate 50.

Accordingly, the restraint plate 80 is connected to the upper surface ofthe supporting portion 10 such that the protrusion portion 81 isprotruded in the downward direction (the direction in which it comesclose to the disk surface).

The magnetic head suspension 2A including the restraint plate 80according to the second embodiment can effectively prevent thesupporting portion of the load beam portion 30 (namely, the portion ofthe load beam portion 30 which is connected to the elastic plate 50)from moving in the direction orthogonal to the disk surface when anexternal impulsive force is applied thereto, which can offer theadvantage of raising the critical acceleration of the impulsive forcewhich triggers the jump of the magnetic head slider 100, in addition tothe advantages of the first embodiment.

FIG. 21 illustrates the results of analyses of the criticalaccelerations in an example (the example 1) of the magnetic headsuspension 1A according to the first embodiment illustrated in FIG. 1and an example (hereinafter, referred to as an example 5) of themagnetic head suspension 2A according to the second embodimentillustrated in FIG. 19, which were resulted from the application ofimpulsive waves (half-sine wave accelerations) having pulse widths of1.00 msec, 1.50 msec and 2.00 msec thereto, on the basis of afinite-element method.

In the example 5, the restraint plate 80 was formed to have a thicknessof 0.045 mm, but the other conditions were the same as those of theexample 1.

As is apparent from FIG. 21, it is revealed that, when impulsive waveshaving acceleration pulse widths of 1.5 msec and 2.0 msec are appliedthereto, the critical acceleration in the example 5 having the restraintplate 80 is higher by about 20 G/gf to 90 G/gf than that in the example1 having no restraint plate 80.

Further, in the present embodiment, as illustrated in FIG. 19, therestraint plate 80 has the single protrusion portion 81. In thisstructure, the protruding portion 81 is brought into contact with theload beam portion 30 at the intersection point between the load bendingcenter line B and the longitudinal center line CL (see FIG. 19A).

Instead of this structure, the restraint plate 80 can have a pluralityof protrusion portions 81. In the case where the restraint plate 80 hasa plurality of protrusion portions 81 as described above, theseplurality of protrusion portions 81 are positioned along the loadbending center line BL and are placed to be symmetrical with thelongitudinal center line CL as a reference.

Also, the protrusion portion 81 can be configured to be contacted withthe load beam portion 30 in a line-to-line manner, instead of beingconfigured to be contacted with the load beam portion 30 in apoint-to-point manner, as illustrated in FIG. 19.

FIG. 22 illustrates an exemplary magnetic head suspension 2B including arestraint plate 81B having a protrusion portion 81B configured to becontacted with the load beam portion 30 in a line-to-line manner FIGS.22A and 22B illustrate a top view of the magnetic head suspension 2B anda cross-sectional view taken along the line b-b in FIG. 22A,respectively.

As illustrated in FIG. 22, the restraint plate 80B has the singleprotrusion portion 81B.

The single protrusion portion 81B is contacted with the load beamportion 30 over a predetermined distance in the widthwise direction ofthe magnetic head suspension, at a state where it is placed along theload bending center line BL and is placed to be symmetrical with thelongitudinal center line CL as a reference.

With this structure, similarly, it is possible to effectively preventthe supporting point of the load beam portion 30 from varying in thedirection orthogonal to the disk surface when an impulsive force isapplied thereto. Further, it is also possible to increase the resonancefrequency, particularly the Torsion-mode frequency (the resonancefrequency in a mode at which the magnetic head slider 100 vibrates inthe seek direction due to the twist of the load beam portion 30).

Instead of the structures, it is also possible to provide a restraintplate 80C structured to be contacted with the load beam portion 30 in asurface-to-surface manner.

FIG. 23 illustrates a magnetic head suspension 2C including therestraint plate 80C. FIGS. 23A to 23C are a top view of the magnetichead suspension 2C, a cross-sectional view taken along the line b-b inFIG. 23A and a cross-sectional view taken along the line c-c in FIG.23A.

The restraint plate 80C is connected to the supporting plate 10 andpositioned on a side of the member forming the load beam portion 30opposite from the elastic plate 50 in the direction orthogonal to thedisk surface so that the member forming the load beam portion 30 issandwiched between the restraint plate 80C and the elastic plate 50,similarly to the restraint plates 80, 80B in FIGS. 19 and 22.

In the illustrated embodiment, the elastic plate 50 is connected to thelower surface of the supporting portion 10 and, also, the load beamportion 30 is connected to the upper surface of the elastic plate 50.Accordingly, the restraint plate 80C is connected to the upper surfaceof the supporting portion 10.

More specifically, as illustrated in FIG. 23, the restraint plate 80Cincludes a connected surface 81 connected to the upper surface (thesurface opposite from the disk surface) of the supporting portion 10, acoupling surface 82C folded in such a direction that it comes close tothe disk surface from the connected surface 81C, and a contact surface83C which is folded from the free-end side of the coupled surface 82Cand is connected to the upper surface (the surface opposite from thedisk surface) of the member forming the load beam portion 30 in asurface-to-surface manner.

A border line between the coupling surface 82C and the contact surface83C is positioned of the load bending center line BL and also issymmetrical with the longitudinal center line CL as a reference.

With this structure, it is also possible to effectively prevent thesupporting point of the load beam portion 30 from varying in thedirection orthogonal to the disk surface when an impulsive force isapplied thereto.

Third Embodiment

Hereinafter, still another embodiment of the magnetic head suspensionaccording to the present invention will be described, with reference tothe attached drawings.

FIGS. 24A to 24C illustrate a top view of the magnetic head suspension3A according to the third embodiment, a bottom view of the same, and across-sectional view taken along the line c-c in FIG. 24A.

Further, in the drawings, the same components as those of the first andsecond embodiments are designated by the same reference characters andwill not be described in detail.

As illustrated in FIG. 24, the magnetic head suspension 3A includes arestriction plate 90 connected to the supporting portion 10 such that itis positioned on a side closer to the disk surface than the base-endside area of the load beam 30, in addition to the structure of themagnetic head suspension 1A according to the first embodiment.

The restriction plate 90 is placed to overlap with at least a portion ofthe balance mass member 60 in a plan view.

By providing the restriction plate 90, it is possible to effectivelyprevent the balance mass member 90, which has been jumped in such adirection that it separates from the disk surface when an impact isapplied the suspension, from swinging back toward the disk surface andimpinging on the disk surface. Further, even if an external impulsiveforce is applied to the balance mass member 60 in such a direction as tocause the balance mass member 60 to come close to the disk surface, itis possible to effectively prevent the balance mass member fromimpinging on the disk surface.

As illustrated in FIG. 24C, the restriction plate 90 is connected to thesupporting portion 10 such that there is a predetermined interval (forexample, 0.1 mm to 0.2 mm) between the restriction plate 90 and thebalance mass member 60, at a normal state where no impact is appliedthereto.

More specifically, the restriction plate 90 includes a first and secondconnected areas 91 a and 91 b connected to the lower surfaces of thepair of supporting pieces 11, and a cover area 91 c extending betweenthe first and second connected areas 91 a and 91 b such that it overlapswith at least a portion of the balance mass member 60 in a plan view.

Further, the cover area 91 c is positioned more proximally to the disksurface than the plane in which there exists the lower surface of thesupporting portion 10, such that there is the predetermined intervalbetween the cover area 91 c and the lower surface of the balance massmember 60.

The restriction plate 90 can be preferably formed from a stainless-steelplate with a thickness in the range of about 0.02 mm to 0.1 mm, forexample.

While, in the present embodiment, there has been described a case wherethe restriction plate 90 is provided in the magnetic head suspension 1Aaccording to the first embodiment, the restriction plate 90 can also beprovided in the magnetic head suspension 2A according to the secondembodiment, as a matter of cause.

Fourth Embodiment

Hereinafter, still another embodiment of the magnetic head suspensionaccording to the present invention will be described, with reference tothe attached drawings.

FIGS. 25A and 25B illustrate a top view and a bottom view of themagnetic head suspension 4A according to the present embodiment,respectively.

Further, FIG. 26 illustrates a partial side view of the magnetic headsuspension 4A. FIGS. 26A and 26B illustrate the magnetic head suspension4A in a state before it is mounted to a data storage device and in astate where it is operated after being mounted to the data storagedevice, respectively.

Further, FIG. 27 and FIG. 28 illustrate, respectively, a perspectiveview and an exploded perspective view illustrating, from above, in astate before it is mounted to the data storage device.

Further, in the drawings, the same components as those of the first tothird embodiments are designated by the same reference characters andwill not be described in detail.

As illustrated in FIGS. 25 to 28, the magnetic head suspension 4Aaccording to the present embodiment includes a balance mass member 460,a load beam portion 430 and an elastic plate 450, instead of the balancemass member 60, the load beam portion 30 and the elastic plate 50 in themagnetic head suspension 1A according to the first embodiment.

FIGS. 29A and 29B illustrate, respectively, a top view and a bottom viewof the balance mass member 460.

As illustrated in FIGS. 25 to 29, the balance mass member 460 includes atip end portion 461 connected to the base-end portion of the load beamportion 430, a base-end portion 463 extending toward the base-end sideof the suspension within the concave portion 12 beyond the elastic plate450, and a center portion 462 positioned between the tip end portion 461and the base-end portion 463 and connected to the elastic plate 450.

That is, as illustrated in FIG. 29, the balance mass member 460 includesthe center portion 462 connected to the elastic plate 450, the tip endportion 461 which is extended toward the tip-end side of the suspensionfrom the center portion 462 and is connected to the load beam portion430, and the base-end portion 463 extending from the center portion 462toward the base-end side of the suspension, in the longitudinaldirection of the magnetic head suspension 4A.

Preferably, as illustrated in FIG. 29, the balance mass member 460 isconfigured such that its base-end portion 463 has a base-end-sidebending portion 463 a and its portion extending from the base-end-sidebending portion 463 a up to the base-end edge is gradually separatedfrom the disk surface with decreasing distance to the base end.

With this structure, when an impact is applied thereto, it is possibleto effectively prevent the balance mass member 460 jumped in such adirection that it separates from the disk surface from impinging on thedisk surface during swaying back toward the disk surface. Further, evenif an external impulsive force is applied to the balance mass member 460in such a direction that it comes close to the disk surface, it ispossible to effectively prevent the balance mass member 460 fromimpinging on the disk surface.

At the base-end-side bending portion 463 a, for example, a groove with adepth equal to ½ to ¾ of the thickness of the balance mass member can beformed in the widthwise direction, as illustrated in FIG. 29. By formingthis groove, it is possible to easily perform the processing for bendingthe balance mass member 460 at the base-end-side bending portion 463 a.

The groove can be formed, with preferable controllability, by etchingthe portion of the balance mass member 460 corresponding to thebase-end-side bending portion 463 a from a single side thereof.

Similarly to the first embodiment, it is preferable that there is therelationship of 0≦Lg≦0.45×. La, more preferably 0≦Lg≦0.3×La and, morepreferably 0≦Lg≦0.2×La in the magnetic head suspension 4A including thebalance mass member 460, wherein Lg is the length in the longitudinaldirection of the magnetic head suspension between the center of gravityWG of the assembly constituted by the load beam portion 430, the flexureportion 40 and the balance mass member 460 and the load bending centerline BL of the first and second extending portions 52 a and 52 b alongthe widthwise direction of the magnetic head suspension and, also, La isthe length in the longitudinal direction of the magnetic head suspensionbetween the load bending center line BL and the center of gravity DG ofthe portion of the aforementioned assembly which is closer to the tipend than the load bending center line BL.

FIG. 30A illustrates a plan view of the elastic plate 450.

The elastic plate 450 has a first and second connected areas 51 a and 51b which are connected to the pair of supporting pieces 11, and a centerarea 52 extending between the first and second connected areas 51 a and51 b as illustrated in FIG. 30A, similarly to in the first embodiment,

The center area 52 has a center connected portion 52 c which ispositioned at the center in the widthwise direction of the magnetic headsuspension 4A, a first extending portion 52 a extending between thecenter connected portion 52 c and the first connected area 51 a, and asecond extending portion 52 b extending between the center connectedportion 52 c and the second connected area 51 b.

The first and second extending portion 52 a and 52 b are shaped to besymmetrical to each other with the longitudinal center line CL of themagnetic head suspension 4A as a reference, similarly to in theembodiments.

Further, the first and second extending portions 52 a and 52 b areshaped to be symmetrical with the load bending center line BL as areference.

In the present embodiment, the elastic plate 450 is connected to thebalance mass member 460, as described above. More specifically, thecenter connected portion 52 c is connected to the center portion 462 ofthe balance mass member 460.

The first and second extending portions 52 a and 52 b are twisted suchthat the tip end side of the load beam portion 430 comes close to thedisk surface in a state before the magnetic head suspension 4A accordingto the present embodiment is mounted to a data storage device (see FIG.26A) and, further, the first and second extending portions 52 a and 52 bare twisted back in a state where the magnetic head suspension 4A isoperated after being mounted to the data storage device (see FIG. 26B),similarly to the magnetic head suspension 1A.

In the magnetic head suspension 4A with the aforementioned structure,the elastic plate 450 supported at its opposite ends functions as theload bending portion 20, similarly to in aforementioned respectiveembodiments.

Accordingly, when an external impulsive force is applied thereto, it ispossible to effectively prevent the supporting point of the load beamportion 430 (namely, the portion of the load beam portion 430 which isconnected to the elastic member 450) from varying in the directionorthogonal to the disk surface, thus suppressing the jump of themagnetic head slider 100 and largely raising the acceleration limit ofthe impulsive force which triggers the jump of the magnetic head slider100.

Preferably, as illustrated in FIG. 30A, each of the first and secondextending portions 52 a and 52 b has outer curved portions 455 having awidth gradually increased with decreasing distance to the correspondingconnected area 51 a, 51 b, and inner curved portions 456 having a widthgradually increased with decreasing distance to the center connectedportion 52 c, at its tip-end side and base-end side.

This structure allows the first and second extending portions 52 a and52 b to perform the twist action in a stable manner, thus reducing thevariation of the spring constant of the elastic plate 450, in comparisonwith the structure having the rectangular-shaped first and secondextending portions 52 a and 52 b (see FIG. 30B).

In the present embodiment, as illustrated in FIG. 30A, the outer curvedportions 455 and the inner curved portions 456 are both formed to havean arc shape.

In this structure, preferably, the radius R of the outer curved portions455 and the inner curved portions 456 is set to within the range of ¼×Wto ⅓×W, assuming that the width between the opposite end portions of thefirst and second extending portions 52 a and 52 b is W.

Instead of this structure, the outer curved portions 455 and the innercurved portions 456 of the respective extending portions 52 a and 52 bat their tip-end side and/or base-end side are formed to have a singleelliptical shape.

In the present embodiment, the load beam portion 430 is positioned moreproximally to the tip-end side of the suspension than the elastic plate450. That is, the load beam portion 430 has a base-end portionterminated at a position closer to the tip-end side of the suspensionthan the elastic plate 450.

In this structure, preferably, the load beam portion 430 and the elasticplate 450 are integrally formed from a single member as illustrated inFIG. 28.

This structure can reduce the number of members and the number ofassembling processes, thereby reducing the cost, and also can improvethe assembling accuracy.

More specifically, as illustrated in FIG. 28, the member forming theload beam portion 430 includes a flange area 430 a having a centerflat-plate portion 431 positioned at the center in the widthwisedirection of the suspension and a pair of flange portions 435 providedat the opposite sides of the center flat-plate portion 431 in thewidthwise direction, an elastic-plate area 430 c forming the elasticplate 450, and a flat-plate shaped coupling area 430 b which couples thecenter flat-plate portion 431 of the flange area 430 a to the tip-endedge of the center connected portion 52 c of the elastic plate 450,wherein these portions are integrally formed.

By coupling the flange area 430 a and the elastic-plate forming area 430c to each other through the flat-plate shaped coupling area 430 b asdescribed above, it is possible to easily form the load beam portion 430having the flange portion 430 and the elastic plate 450 from a singlemember.

The coupling area 430 b is formed to have a flat-plate shape asdescribed above and therefore has rigidity lower than that of the flangearea 430 a.

To cope with this point, in the present embodiment, as illustrated inFIG. 27, the tip-end portion 461 of the balance mass member 460 isconnected to the center flat-plate portion 431, at a state where thetip-end portion 461 of the balance mass member 460 is interposed betweenthe pair of flange portions 435.

That is, in the present embodiment, the balance mass member 460 alsofunctions as a reinforcing member which reinforces the rigidity of thecoupling area 430 b.

Further, since the flange area 430 a and the elastic-plate area 430 care coupled to each other through the flat-plate shaped coupling area430 b and, also, the tip-end portion 461 of the balance mass member 460is connected to the center flat-plate portion 431 with the tip-endportion 461 interposed between the pair of flange portions 435, it ispossible to easily perform the process for bending the magnetic headsuspension 4A at the coupling area 430 b, thereby facilitating theoperations for adjusting the position of the center line of the twistingmode of the magnetic head suspension 4A with respect to the apex of thedimple 31.

That is, even in the event of the occurrence of vibrations of themagnetic head suspension 4A in a twisting mode, when the center line ofthe vibrations in the twisting mode passes through the apex of thedimple 31, it is possible to effectively prevent the deviation of theposition of the magnetic head slider 100 due to the vibrations in theaforementioned twisting mode.

The positioning of the center line of the twisting mode can be performedby applying a bending process to the load beam portion 430 and thebalance mass member 460 at a position closer to the tip-end side of thesuspension than the load bending portion 20.

To cope with this point, in the present embodiment, the flange area 430a and the elastic-plate area 430 c are coupled to each other through theflat-plate shaped coupling area 430 b, as described above. This enablesperforming the process for bending the magnetic head suspension 4A atthe coupling area 430 b which does not have the flange portion 435,thereby enabling the bending process with higher accuracy.

More preferably, as illustrated in FIG. 28, the coupling area 430 b isformed to have a width smaller than that of the base-end portion of theflange area 430 a.

With this structure, it is possible to perform more easily theaforementioned bending process on the coupling area 430 b.

More preferably, as illustrated in FIG. 29, the balance mass member 460has a tip-end-side bending portion 461 a at the portion of the tip-endportion 461 which corresponds to the coupling area 430 b.

The tip-end-side bending portion 461 a is structured to have a thicknesssmaller than those of the other areas.

With this structure, it is possible to easily perform the bendingprocess on the balance mass member 460 and the load beam portion 430 atthe coupling area 430 b, at a state where the balance mass member 460 isconnected to the load beam portion 430.

The tip-end-side bending portion 461 a can be formed to be a groovehaving a depth equal to ½ to ¾ of the thickness of the aforementionedbalance mass member along the widthwise direction, for example, asillustrated in FIG. 29.

The groove can be formed, with preferable controllability, by etchingthe portion of the balance mass member 460 corresponding to thetip-end-side bending portion 461 a from a single side thereof.

Fifth Embodiment

Hereinafter, still another embodiment of the magnetic head suspensionaccording to the present invention will be described, with reference tothe attached drawings.

FIGS. 31A and 31B illustrate a top view and a bottom view of themagnetic head suspension 5A according to the present embodiment,respectively.

Further, FIG. 32 illustrates a partial side view of the magnetic headsuspension 5A. FIGS. 32A and 32B illustrate the magnetic head suspension5A in a state before it is mounted to a data storage device and in astate where it is operated after being mounted to the data storagedevice.

Further, FIG. 33 illustrates a perspective view illustrating themagnetic head suspension 5A in a state where it is operated after beingmounted to the data storage device, from the disk-surface side.

Further, in the drawings, the same components as those of the first tofourth embodiment are designated by the same reference characters andwill not be described in detail.

The magnetic head suspension 5A according to the present embodimentincludes an elastic plate 550, instead of the elastic plate 450 in themagnetic head suspension 4A according to the fourth embodiment.

FIG. 34 illustrates a perspective view illustrating the elastic plate550, from the disk-surface side.

The elastic plate 550 includes the first and second connected areaswhich are connected to the pair of supporting pieces 11, and a centerarea 52 extending between the first and second connected areas 51 a and51 b. The center area 52 includes the center connected portion 52 cwhich is connected to the balance mass member 460, the first extendingportion 52 a extending between the center connected portion 52 c and thefirst connected area 51 a, and the second extending portion 52 bextending between the center connected portion 52 c and the secondconnected area 51 b.

The elastic plate 550 is different from the elastic plates 50 and 450according to the respective embodiments, in that the center connectedportion 52 c has the following structures.

That is, in the present embodiment, as illustrated in FIG. 34, thecenter connected portion 52 c includes a tip-end-side flat-surfaceportion 551 which is positioned on a tip-end side and is connected tothe center portion 462 of the balance mass member 460 at an attitudeparallel to the center portion 462, a center flat-surface portion 552which is extended from the tip-end-side flat-surface portion 551 towardthe base-end side of the suspension and which is inclined with respectto the tip-end-side flat-surface portion 551 such that it graduallyseparates from the center portion 462 of the balance mass member 460with increasing distance from the tip-end side toward the base-end sideand to which the first and second extending portions 52 a and 52 b areconnected, and a base-end-side flat-surface portion 553 which isextended toward the base-end side of the suspension from the centerflat-surface portion 552 with a bending portion 554 interposedtherebetween and is connected to the center portion 462 of the balancemass member 460 at an attitude parallel to the center portion 462.

The elastic plate 550 is structured such that, in a state before themagnetic head suspension 5A is mounted to a data storage device, thecenter flat-surface portion 552 is positioned within the same plane asthe plane in which there exist the first and second extending portions52 a and 52 b and the first and second connected areas 51 a and 51 band, in a state where the magnetic head suspension 5A is operated afterbeing mounted to the data storage device, the first and second extendingportions 52 a and 52 b are twisted, thus generating the load.

With the magnetic head suspension 5A including the elastic plate 550having the aforementioned structure, it is possible to generate the loadin a state where it is operated after being mounted to the data storagedevice, without performing a process for twisting the elastic plate 550before it is mounted to the data storage device. This can reduce thenumber of processes, thus reducing the cost, and also enables stablycontrolling the load.

That is, in the magnetic head suspension 4A according to the fourthembodiment, before it is mounted to a data storage device, the elasticplate 450 is subjected to a twisting, process such that the tip-end sideof the load beam portion 430 comes close to the disk surface and, also,in a state where it is operated, the elastic plate 450 is twisted backdue to the air pressure, thereby generating the load.

On the contrary, in the magnetic head suspension 5A according to thepresent embodiment, in a state before it is mounted to a data storagedevice, the load beam 30 is inclined with respect to the supportingportion 10 by an angle corresponding to the angle of the inclination ofthe center flat-surface portion 552 with respect to the tip-end-sideflat-surface portion 551 such that the tip-end side of the load beamportion 30 comes close to the disk surface, while the elastic plate 550is not twisted, and, also, in a state where it is operated after beingmounted to the data storage device, the tip-end side of the load beamportion 30 is pushed upwardly by the air pressure, which causes thefirst and second extending portions 52 a and 52 b to be twisted, therebygenerating the load.

This can eliminate the process for twisting the elastic plate 550 andalso can stabilize the load, in comparison with the structures in whichthe elastic plate is twisted back to generate the load.

Although, in the present embodiment, the elastic plate 550 is formed asa member separated from the load beam portion 30, the elastic plate 550and the load beam portion 30 can be integrally formed from a singlemember, as in the fourth embodiment.

Further, although, in the present embodiment, there has been exemplifiedthe structure which provides the elastic plate 550 in the magnetic headsuspension 4A according to the fourth embodiment, the elastic plate 550can also be applied to the magnetic head suspension 1A according to thefirst embodiment, as a matter of cause.

In the case where the elastic plate 550 is applied to the magnetic headsuspension 1A according to the first embodiment, the tip-end-sideflat-surface portion 551 is connected to the member forming the loadbeam portion 30 at an attitude parallel thereto, the center flat-surfaceportion 552 is inclined with respect to the tip-end-side flat-surfaceportion 551 such that it gradually separates from the member forming theload beam portion 30 with increasing distance from the tip-end sidetoward the base-end side, and the base-end-side flat-surface portion 553is extended from the center flat-surface portion 552 toward the base-endside of the suspension through the bending portion 554 and is connectedto the member forming the load beam portion 30.

Sixth Embodiment

Hereinafter, still another embodiment of the magnetic head suspensionaccording to the present invention will be described, with reference tothe attached drawings.

FIGS. 35A and 35B illustrate a top view and a bottom view of themagnetic head suspension 6A according to the embodiment, respectively.

Further, in the drawings, the same components as those of the first tofifth embodiments are designated by the same reference characters andwill not be described in detail.

In the respective embodiments explained above, the pair of supportingpieces 11 have a constant width over the entire area in the longitudinaldirection from the base-end side to the tip-end side.

On the contrary, as illustrated in FIG. 35, the magnetic head suspension6A according to the present embodiment includes a pair of supportingpieces 611 having base-end portions 611 a and tip-end portions 611 b towhich the elastic plate 50 is connected, wherein the base-end portions611 a have widths greater than those of the tip-end portions 611 b.

That is, the magnetic head suspension 6A includes a supporting portion610, instead of the supporting portion 10 in the magnetic headsuspension 1A according to the first embodiment.

The supporting portion 610 includes the pair of supporting pieces 611extending from its opposite sides in the widthwise direction of themagnetic head suspension 6A toward the tip-end side of the suspension,and a concave portion 12 which is defined by the pair of supportingpieces 611 to be opened toward the tip-end side of the suspension, asillustrated in FIG. 35.

Further, the pair of supporting pieces 611 includes the base-endportions 611 a positioned on the base-end side of the suspension, andthe tip-end portions 611 b which are positioned more proximally to thetip-end side of the suspension than the base-end portion 611 a and towhich the elastic plate 50 is connected, wherein the base-end portions611 a have widths greater than those of the tip-end portions 611 b.

With the magnetic head suspension 6A having the aforementionedstructure, it is possible to raise the resonance frequency of thesupporting portion 610 in the twisting mode, out of the vibration modeswhich can occur in the magnetic head suspension, thus improving thepositioning accuracy in moving the magnetic head slider 100 to a desiredtrack.

Further, although, in the present embodiment, there has been exemplifiedthe structure which provides the pair of supporting pieces 611 in themagnetic head suspension 1A according to the first embodiment, the pairof supporting pieces 611 can also be applied to the magnetic headsuspensions 2A to 5A according to the other embodiments, as a matter ofcause.

This specification is by no means intended to restrict the presentinvention to the preferred embodiment and the modified embodiment setforth therein. Various modifications to the suspension for supportingthe magnetic head slider may be made by those skilled in the art withoutdeparting from the spirit and scope of the present invention as definedin the appended claims.

1. A magnetic head suspension comprising: a load bending portiongenerating a load for pressing a magnetic head slider toward a disksurface, wherein the load bending portion comprises anelastically-deformable elastic plate; a load beam portion transmittingthe load to the magnetic head slider, wherein the load beam portion isconnected to the elastic plate, and wherein the load beam portionincludes a connected area to which the elastic plate is connected, atip-end area extending from the connected area toward the tip-end sideof the suspension, and a base-end area extending from the connected areatoward the base-end side of the suspension; a balance mass memberconnected to the base-end area of the load beam portion; a supportingportion supporting the load beam portion through the load bendingportion, wherein the supporting portion includes a pair of supportingpieces extending from opposite sides of the supporting portion in thewidthwise direction to a tip-end side of the suspension, and a concaveportion which is defined by the pair of supporting pieces and is openedtoward the tip-end side of the suspension; a flexure portion connectedto the load beam portion and supporting the magnetic head slider; and arestriction plate connected to the supporting portion so as to bepositioned on a side closer to the disk surface than the base-end sidearea of the load beam portion, wherein the restriction plate is placedto overlap with at least a portion of the balance mass member in a planview, wherein the elastic plate is connected to the pair of supportingpieces at a first end and a second end in the widthwise direction of themagnetic head suspension, wherein the elastic plate includes first andsecond connected areas which are respectively connected to the pair ofsupporting pieces, and a center area extending between the first andsecond connected areas, and wherein the center area includes a centerconnected portion to which the load beam portion is connected, a firstextending portion extending between the center connected portion and thefirst connected area, and a second extending portion extending betweenthe center connected portion and the second connected area, the secondextending portion being symmetrical with respect to the first extendingportion with a longitudinal center line of the magnetic head suspensionas a reference, and wherein a length Lg and a length La have arelationship of 0≦Lg≦0.3×La, the length Lg being a length in thelongitudinal direction of the magnetic head suspension between a centerof gravity of the load beam portion, the flexure portion, and thebalance mass member, and a load bending center line of the first andsecond extending portions along the widthwise direction of thesuspension, and the length La being a length in the longitudinaldirection of the suspension between the load bending center line, andthe center of gravity of a tip-end side portion of the assembly which iscloser to the tip-end side of the suspension than the load bendingcenter line.
 2. A magnetic head suspension comprising: a load bendingportion generating a load for pressing a magnetic head slider toward adisk surface, wherein the load bending portion comprises anelastically-deformable elastic plate; a load beam portion transmittingthe load to the magnetic head slider, wherein the load beam portion isconnected to the elastic plate, and wherein the load beam portionincludes a connected area to which the elastic plate is connected, atip-end area extending from the connected area toward the tip-end sideof the suspension, and a base-end area extending from the connected areatoward the base-end side of the suspension; a balance mass memberconnected to the base-end area of the load beam portion; a supportingportion supporting the load beam portion through the load bendingportion, wherein the supporting portion includes a pair of supportingpieces extending from opposite sides of the supporting portion in thewidthwise direction to a tip-end side of the suspension, and a concaveportion which is defined by the pair of supporting pieces and is openedtoward the tip-end side of the suspension; and a flexure portionconnected to the load beam portion and supporting the magnetic headslider, wherein the elastic plate is connected to the pair of supportingpieces at a first end and a second end in the widthwise direction of themagnetic head suspension, wherein the elastic plate includes first andsecond connected areas which are respectively connected to the pair ofsupporting pieces, and a center area extending between the first andsecond connected areas, and wherein the center area includes a centerconnected portion to which the load beam portion is connected, a firstextending portion extending between the center connected portion and thefirst connected area, and a second extending portion extending betweenthe center connected portion and the second connected area, the secondextending portion being symmetrical with respect to the first extendingportion with a longitudinal center line of the magnetic head suspensionas a reference, wherein a length Lg and a length La have a relationshipof 0≦Lg≦0.3×La, the length Lg being a length in the longitudinaldirection of the magnetic head suspension between a center of gravity ofthe load beam portion, the flexure portion, and the balance mass member,and a load bending center line of the first and second extendingportions along the widthwise direction of the suspension, and the lengthLa being a length in the longitudinal direction of the suspensionbetween the load bending center line, and the center of gravity of atip-end side portion of the assembly which is closer to the tip-end sideof the suspension than the load bending center line, wherein the balancemass member includes a connected portion connected to the load beamportion and a base-end-side bending portion positioned on a side closerto the base-end side of the suspension than the connected portion, andwherein the balance mass member is configured so that a portionextending from the base-end-side bending portion up to a base-end edgeis gradually separated from the disk surface with decreasing distance tothe base-end edge than the connected portion.
 3. The magnetic headsuspension according to claim 2, wherein the base-end-side bendingportion has a thickness smaller than those of the other areas of thebalance mass member.